Berger



UNITED STATES PATENT OFFIcE.

FRITZ ULLHANN, OF FUERTH, GERMANY, ASSIGNOR TO ARON LANDS- BERGER, OF BERLIN, GERMANY.

PROCESS OF PURIFYING ACETYLENE GAS.

SPECIFICATION forming part of Letters Patent No. 625,4?9, dated May 23, 1899.

Application filed October 17, 1898. Serial No. 693,778. (No specimens) To all whom it may concern.-

Be it known that I, FRITZ ULLMANN, chemist, a subject of the Emperor of Germany, and a resident of No. 42 Marktstrasse, Fuerth, Bavaria, in the Empire of Germany, have invented a certain new and useful Improved Process of Purifying Acetylene Gas, of which the following is an exact, full, and clear description.

This invention relates to a process of 'purifying acetylene gas. According to the statements of literature chromic acid oxidizes acetylene gas to acetic acid; but according to my experiments an aqueous or acetic solution of chromic acid which was obtained from chromic acid itself or from acidified chromates or bichromates acts upon the impure acetylene gas as the same is, for instance, obtained from carbid in such a manner that only the impu1'itiesas, for instance, sulfid of hydrogen and phosphoreted hydrogen-are oxidized. Since the action takes effect in an acidic solution, the impure acetylene gas is also deprived of the alkaline components-as, for instance, ammonia and basic polymerized compounds. According to the present invention this property of the chromic-acid solution is utilized for purifying acetylene gas in a simple and cheap manner.

The invention is carried out in such a manner that the acetylene gas to be purified is passed or conducted through suitable washing apparatus in which is present the oxidation liquid either as such or absorbed by pumice-stone or any other suitable material.

The degree of concentration of the chromicacid solution may vary within wide limits. Good results have been obtained from the following solutions: first, a solution containing twenty-five parts sodium bichromate and one hundred parts ten-per-cent. sulfuric acid; second, a solution containing thirty parts chromic acid, ninety-five parts water, and five parts sulfuric acid; third, a solution containing fifty parts chromic acid, fifty parts water, and one hundred parts glacial or crystallizable acetic acid. Such solutions are utilized in suitable cleansing or washing apparatus. The degree of concentration as against the above statements may be varied at pleasure Without the result undergoing any change of moment.

Having now particularly described and ascertained-the nature of the said invention, I declare that what I claim, and Wish to secure by Letters Patent, is-

The herein-described process of purifying acetylene gas consisting in treating impure acetylene gas with oxidizing chromic compounds in which the chrome is present as an acidifier, for instance, with chromic acid or aqueous or acidified chromic-acid solution or acidified biohromate solution for the purpose of oxidizing the impurities of the acetylene.

In witness whereof I have hereunto set my hand in presence of two witnesses.

FRITZ ULLMANN.

Witnesses:

BENJ. H. RIDGELY, E. F. BARRY. 

